http://www.nginxtips.com/install-ruby-2-rails-centos6-rmv/

CentOSRubyonRails

// Try downloading the signatures
command curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -

// Install RVM
curl -L get.rvm.io | bash -s stable

// Setup RVM Environment
source /home/huangchienchang01/.rvm/scripts/rvm

// Install Ruby
rvm install 2.2.2

// mysql.h is missing
sudo yum install mysql-devel

// Install missing gems
bundle install

// Check Current Ruby Version
ruby -v

// Check Current Rails Version
rails -v

// Make server run as a Daemon
rails server -p 3000 -d

// Check Ruby on Rails process
ps aux | grep ruby | grep rails
// 1006      1805  0.0  1.5 293732 59284 ?        Sl   06:19   0:00 /home/huangchienchang01/.rvm/rubies/ruby-2.2.2/bin/ruby bin/rails server -d